Real? Myth? J/w since I have this random switch with 2 green wires coming out of the back, one to ground and the other disappears into the dashboard. Don't have electric fans, no rear defog, nothing visible changes when it's switched. o No:
No such thing. The contact is for the transmission controlled spark advance, a pollution device. There is a pressure switch on the valvebody. That works in conjunction with the thermovaccum switch on the intake manifold to eliminate vacuum advance in 1st and 2nd gears. In 3rd gear you get normal vacuum advance. Some 70's THM 400's have 2 contacts for the same reason, and they are not SP's.
What car is it in and what year is the transmission? It could be a 350C which is a TH350 with a lock up converter.
switch location??? If the switch location is by the dipstick tube on the trans, YES it is for spark crap on smog veehikles.
2 wires? Bringing this thread from the dead.... I just yanked the th350 out of my 1983 regal wagon that had a 3.8 in front of it. There is a plug on the drivers side of the trans with two wires coming out of it. The two wires went into the computer system, but I ripped that out completely (the computer and harness) since I will be using my 67 340. I saved the plug just incase.... Should I tie those 2 wires into anything or just leave it unplugged? I'm guessing leave it unplugged.... Thanks in advance (again)
Re: 2 wires? It's probably a THM 350C, lockup torque converter. If you are using the torque converter that was in it, I'd think you want to be able to lock up the converter on the highway.
